1PROBE::IOBLOCK.REQ(3stap)IO Scheduler and block IO TapsPROBE::IOBLOCK.REQ(3stap)
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NAME

6       probe::ioblock.request - Fires whenever making a generic block I/O
7       request.
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SYNOPSIS

10       ioblock.request
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VALUES

13       hw_segments
14           number of segments after physical and DMA remapping hardware
15           coalescing is performed
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17       opf
18           operations and flags
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20       idx
21           offset into the bio vector array
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23       rw
24           binary trace for read/write request
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26       p_start_sect
27           points to the start sector of the partition structure of the device
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29       bdev
30           target block device
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32       size
33           total size in bytes
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35       phys_segments
36           number of segments in this bio after physical address coalescing is
37           performed
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39       devname
40           block device name
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42       vcnt
43           bio vector count which represents number of array element (page,
44           offset, length) which make up this I/O request
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46       ino
47           i-node number of the mapped file
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49       flags
50           see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
51           RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
52           error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
53           BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
54           pages BIO_EOPNOTSUPP 7 not supported
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56       name
57           name of the probe point
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59       bdev_contains
60           points to the device object which contains the partition (when bio
61           structure represents a partition)
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63       sector
64           beginning sector for the entire bio
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CONTEXT

67       The process makes block I/O request
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SEE ALSO

70       tapset::ioblock(3stap)
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74SystemTap Tapset Reference       October 2018        PROBE::IOBLOCK.REQ(3stap)
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